Substrate processing apparatus

ABSTRACT

Support arrangement for supporting a radiation projection system in a substrate processing apparatus, the support arrangement comprising:
     a support body for supporting the radiation projection system;   electrical wiring for supplying voltages to components within the radiation projection system and/or for supplying control data for modulation of radiation to be projected onto a target surface by the radiation projection system;   optical fibers, for supplying control data for modulation of radiation to be projected onto a target surface by the radiation projection system, and   a cooling arrangement comprising one or more fluid conduits for cooling the radiation projection system;   the electrical wiring, the optical fibers, and the cooling arrangement being at least partly accommodated in and/or supported by the support body.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of application Ser. No.15/642,359, entitled “Substrate Processing Apparatus,” filed 6 Jul.2017, which is a continuation of U.S. patent application Ser. No.14/342,542, filed on 23 Jun. 2014, which in turn is a 371 of PCTapplication number PCT/EP2012/067879 filed on 12 Sep. 2012, which claimspriority from U.S. provisional application No. 61/533,362 filed on 12Sep. 2011. All abovementioned applications are hereby incorporated byreferences in their entireties.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The invention relates to a substrate processing apparatus, such as alithographic apparatus or an inspection apparatus.

2. Description of the Related Art

In the semiconductor industry, an ever increasing desire exists tomanufacture smaller structures with high accuracy and reliability. Inlithography systems this desire results in extremely high demands withrespect to positioning and orientation. External vibrations caused byother machines in a fab environment and/or electrical circuitry may havea negative influence on the positioning accuracy within the lithographicapparatus. Similarly, vibrations within a lithographic apparatus, forexample caused by stage movement, may have a negative influence on suchaccuracy.

Reduction of vibrations may be realized by isolating the source and thecomponents used to manipulate the radiation, i.e. a radiation projectionsystem or “column”, from the environment. Similarly, the substrate to beprocessed, in combination with the support structure on which thesubstrate is placed, may be vibrationally decoupled from the stage.Vibration decoupling may be achieved using bearings, spring elementsand/or other components. The precise selection and placement of suchcomponents depends on the design at hand.

The reduction of feature sizes in combination with the desire tomaintain the present day throughput in semiconductor processing, oftenresults in an increased heat load for both the substrate supportstructure and components within the radiation projection system of thesemiconductor processing apparatus. In some cases, active cooling bymeans of a cooling fluid running through one or more conduits, isdesirable to obtain sufficient cooling. Unfortunately, the use ofcooling conduits largely undoes the vibration decoupling of the elementbeing cooled.

BRIEF SUMMARY OF THE INVENTION

It is desirable to provide active cooling to a radiation projectionsystem within a substrate processing apparatus, such as a lithographicapparatus or inspection apparatus, without jeopardizing the design ofthe apparatus with respect to vibrational decoupling from externalvibrations. For this purpose, an embodiment of the invention provides asubstrate processing apparatus, such as a lithographic apparatus or aninspection apparatus, comprising: a support frame; a radiationprojection system for projecting radiation onto a substrate to beprocessed, the radiation projection system comprising a coolingarrangement and being supported by and vibrationally decoupled from thesupport frame such that vibrations of the support frame above apredetermined maximum frequency are substantially decoupled from theradiation projection system; and a substrate support structure with asurface for supporting the substrate to be processed; the substrateprocessing apparatus further comprising a fluid transfer system forproviding fluid to and removing fluid from the cooling arrangement ofthe radiation projection system, wherein the fluid transfer systemcomprises at least one tube fixed at at least two points within theapparatus, the fluid transfer system comprising a flexible portionextending between the two fixed points and including at least one tube,a first one of the fixed points being fixed relative to the radiationprojection system and a second one of the fixed points being moveablerelative to the radiation projection system, wherein at least asubstantial part of the flexible portion extends in two dimensions overa plane substantially parallel to the surface of the substrate supportstructure for supporting the substrate to be processed, and wherein thestiffness of the flexible portion between the two points is adapted tosubstantially decouple vibrations at the second fixed point which areabove the predetermined maximum frequency from the first fixed point.The use of a fluid transfer system with a flexible portion of which asubstantial part extending in a plane substantially parallel to theradiation receiving surface of a substrate to be processed and with astiffness resulting in a sufficient attenuation of vibrations above apredetermined maximum frequency enables the maintaining of an effectivedecoupling of vibrations of the radiation projection system from thesupport frame while allowing the supply of fluid to the radiationprojection system, for example for cooling purposes. In embodimentswhere a moveable substrate support structure is used, the predeterminedmaximum frequency may depend on the maximum frequency that can befollowed by the control system. In some embodiments, the second one ofthe fixed points is fixed relative to the support frame.

The flexible portion of the fluid transfer system may have apredetermined maximum stiffness, for example a predetermined maximumstiffness lower than 500 N/m, more preferably lower than 400 N/m. Themaximum stiffness may be determined by the design requirements of thesystem at hand.

Providing a predetermined stiffness for the flexible portion of thefluid transfer system may include different selections of suitableparameters and conditions. For example, the length, diameter and wallthickness of the at least one tube may be suitably selected.Alternatively, or additionally, the curvature of the at least one tubemay be suitably selected. Furthermore, as the stiffness of the flexibleportion may depend on the fluid that is transferred through the fluidtransfer system during operational use, the fluid transfer system maycomprise a fluid supply system for regulating parameters of the fluidflow in the fluid transfer system. Exemplary parameters include, but arenot limited to fluid type, fluid volume and fluid pressure.

Suitable materials for the at least one tube would be perfluoroalkoxy(PFA) and polytetrafluoroethylene (PTFE), the latter being known underthe trade name Teflon®. In some embodiments, PFA is preferred because itis melt-processable using conventional processing techniques includingbut not limited to injection molding and screw extrusion.

In some embodiments, the support frame, the radiation projection system,the substrate support structure and the fluid transfer system are placedin a vacuum chamber. In such embodiments, the extent of heat removalaway from the radiation projection system may almost entirely depend onthe capacity and performance of the fluid transfer system because activeheat removal is about the only effective heat transfer mechanismavailable.

The at least one tube may be oriented in a curved fashion in the planesubstantially parallel to the surface of the substrate supportstructure. In some embodiments, the at least one tube may form a loop.Preferably, the curvature of the at least one tube substantiallycorresponds to the natural curvature of the at least one tube obtainedduring fabrication thereof. By using the natural curvature of the tubevibrations may be attenuated most effectively. Furthermore, resilientforces attempting to reshape the tube in its natural way are absent.

In some embodiments, the apparatus comprises at least one suspensionholder comprising a support structure for holding the at least one tubeat a location along its length, the support structure beingvibrationally decoupled from the support frame for vibrations in adirection within the plane substantially parallel to the surface of thesubstrate support structure, as well as in a rotational direction aboutan axis substantially perpendicular to that plane. Such suspensionholder limits tube bending under the influence of gravity.

In some embodiments, the fluid transfer system comprises a plurality oftubes. The tubes may have different diameters. If a suspension holder isused, the tubes with the larger diameter may be more centrally supportedto increase the stability of the flexible portion of the fluid transfersystem as compared to an arrangement in which these tubes are supportedat a less central position.

The end portions of the at least one tube may be oriented in a directionsubstantially perpendicular to the plane of the surface of the substratesupport structure for supporting the substrate to be processed. Suchorientation may reduce the footprint of the fluid transfer system.

In some embodiments of the invention, the at least one tube comprises atleast two straight portions and at least one corner portion between thetwo points, wherein the at least two straight portions are flexiblecompared to the at least one corner portion, and wherein the length ofthe straight portions makes up a largest part of the length of the atleast one tube. The relatively flexible straight portions enablevibrational decoupling, whereas the relatively stiff corner portionprovides sufficient structural integrity to transfer fluid through thefluid transfer system in a reliable and controllable fashion. The use ofmore than one tube may improve homogeneous spreading of fluid throughoutthe radiation projection system.

Preferably, the lengths of the straight portions make up a largest partof the tube lengths. To obtain a fluid transfer system with limitedstiffness, preferably, the lengths of the straight portions make up alargest part of the tube lengths, for example at least 70%. The straightportions of each tube are preferably free of contacting straightportions of other tubes to minimize tube-tube interactions.

In some embodiments, the at least one corner portion comprises astiffening member provided with an opening for transferring fluid arounda corner. The stiffening member helps to strengthen the corner portionso that the corner portion can sustain a pressure increase when fluidruns through the one or more tubes. In some circumstances, a stiffeningmember may be needed to prevent tube straightening as a result of suchpressure increase. The stiffening member may be connected to the supportframe by means of a spring element to obtain sufficient structuralintegrity in combination with a vibrational decoupling of the stiffeningmember from the support frame. The stiffening member may comprisealuminum.

In some embodiments, the support frame, the radiation projection system,the substrate support structure, and the fluid transfer system areplaced in a vacuum chamber. Many substrate processing applications, suchas electron beam lithography, require substrate processing under vacuumconditions. The fluid transfer system may then be surrounded by ahousing to limit a flow from particles released from the tubes towardsinto the vacuum. The housing may be a tubular housing suitable foraccommodating the fluid transfer system.

At an end at which the one or more tubes are attached to the coolingarrangement, the housing may be provided with a membrane for separatinga space within the housing from external influences, the membrane beingprovided with one or more openings through which the one or more tubesprotrude. The membrane further avoids the spreading of particlesoriginating from the fluid transfer system into the vacuum. The membranemay be provided with flexible portions in areas within the openings,wherein the flexible portions extend from the membrane onto the tubes.The flexible portions ensure a vibrational decoupling between themembrane and the tubes, as well as further reduce the flow ofcontaminants from the space within the housing towards a vacuumenvironment. Alternatively, or additionally, particle contamination maybe reduced by providing the housing with an outlet that is connectibleto a pump, preferably a vacuum pump.

In some embodiments, the apparatus further comprises: a support body foraccommodating the radiation projection system; and an intermediate bodyconnected to the support frame by means of at least one spring element;wherein the support body is connected to the intermediate body by meansof at least one pendulum rod. The at least one spring element may be aleaf spring. A leaf spring has well-defined vibrational properties. Theleaf spring may comprise at least two substantially parallel elongatedplates. The thickness and length of these plates largely determine theeigenfrequency of the leaf spring. In some embodiments, the support bodyis provided with side walls surrounding the radiation projection system,wherein the side walls comprising a shielding material for shielding theradiation projection system from external electromagnetic fields.

The radiation projection system may be a multi-beamlet charged particlelithographic apparatus. In particular, such multi-beamlet chargedparticle lithographic apparatus may comprise: a beam generator forgenerating a plurality of charged particle beamlets; a beamlet blankerarray for patterning the plurality of beamlets in accordance with apattern; and a projection system for projecting the patterned beamletsonto a target surface of a substrate provided on the target supportstructure.

In some embodiments, the substrate support structure is a moveablesubstrate support structure. The apparatus may then further comprise acontrol system for moving the substrate support structure with respectto the radiation projection system.

Some embodiments of the invention are related to a substrate processingapparatus, such as a lithographic apparatus or an inspection apparatus,comprising: a support frame; a radiation projection system forprojecting radiation onto a substrate to be processed, being supportedby and vibrationally decoupled from the support frame such thatvibrations of the support frame above a predetermined maximum frequencyare substantially decoupled from the radiation projection system; afluid transfer system for transferring fluid to and removing fluid fromthe radiation projection system; and a substrate support structureprovided with a surface for supporting the substrate to be processed;wherein the fluid transfer system comprises one or more tubes fortransferring fluid, wherein a portion of the one or more tubes extendsin a two dimensions over a plane substantially parallel to the surfaceof the substrate support structure for supporting the substrate to beprocessed. The portion of the one or more tubes may extend over theplane in the form of a loop.

In some embodiments, the apparatus further comprises at least onesuspension holder for holding the portion of the one or more tubesextending in two dimensions. Furthermore, an additional support framethat is connected to the support frame may be provided for supportingthe at least one suspension holder.

In some embodiments, the radiation projection system comprises a coolingarrangement. In these embodiments, the fluid transfer system is adaptedfor transferring cooling fluid to and removing cooling fluid from thecooling arrangement. The use of a cooling arrangement is particularlyuseful in next generation lithography applications, such as lithographyapplications using a plurality of charged particle beamlets.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of exampleonly, with reference to the accompanying schematic drawings in which:

FIG. 1 shows a simplified schematic drawing of a substrate processingapparatus;

FIG. 2 schematically shows a substrate processing apparatus that may beused in embodiments of the invention;

FIG. 3 shows a more detailed view of a portion of the substrateprocessing apparatus of FIG. 2;

FIG. 4 shows an elevated side view of a support body;

FIG. 5 schematically shows a fluid transfer system according to anembodiment of the invention;

FIG. 6 schematically shows the fluid transfer system of FIG. 5 connectedto a support frame;

FIG. 7 schematically shows a suspension holder that may be used in thefluid transfer system of FIG. 5;

FIG. 8 schematically shows a fluid transfer system according to anotherembodiment of the invention;

FIG. 9 schematically shows a cross-sectional view of an embodiment of acorner portion for use in the fluid transfer system of FIG. 8;

FIG. 10 schematically shows a cross-sectional view of an embodiment of astiffening member that may be used in the fluid transfer system of FIG.8;

FIG. 11 schematically shows an elevated side view of a fluid transfersystem according to yet another embodiment of the invention; and

FIG. 12 schematically shows a cross-sectional view of an embodiment of aconnection between the fluid transfer system of FIG. 11 with a coolingarrangement.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The following is a description of various embodiments of the invention,given by way of example only and with reference to the figures. Thefigures are not drawn to scale and are merely intended for illustrativepurposes.

FIG. 1 shows a simplified schematic drawing of a substrate processingapparatus 10 that may be used in embodiments of the invention. Thesubstrate processing apparatus 10 comprises a radiation projectionsystem 20 for projecting radiation onto a substrate, such as a wafer, tobe processed. The radiation projection system 20 may include a beamletgenerator for generating a plurality of beamlets, a beamlet modulatorfor patterning the beamlets to form modulated beamlets, and a beamletprojector for projecting the modulated beamlets onto a surface of atarget. The components within the radiation projection system 20 aretypically arranged in a column and are usually referred to as theelectron-optical column or optical column, but will be referred toherein as simply the “column”. The radiation projection system 20 may bearranged to project any kind of suitable radiation, for example thesystem 20 may project of charged particle beams, optical beams, or othertypes of beams.

The substrate processing apparatus 10 further comprises a substratesupport structure 30 for supporting the substrate to be processed. Thesubstrate support structure 30 may be a moveable substrate supportstructure. The apparatus 10 may then further comprise a control system40 for moving the substrate support structure 30 with respect to theradiation projection system 20. The control system 40 may base themovement on position information obtained by measurements within theradiation projection system 20, for example by the use ofinterferometry.

Hereafter, embodiments of the invention will be described in relation toa lithographic apparatus, although it may also be applied for aninspection apparatus, and the like. In particular, reference is made toa multi-beam charged particle lithographic apparatus. As schematicallyshown in FIG. 1, such apparatus comprises a beam generator 21 forgenerating a plurality of charged particle beamlets, a beamlet blankerarray 22 for patterning the plurality of beamlets in accordance with apattern, and a projection system 23 for projecting the patternedbeamlets onto a target surface of a substrate provided on the targetsupport structure. An example of such apparatus may be found ininternational patent publication WO2009/127658, a copy of which isherein incorporated by reference in its entirety.

FIG. 2 schematically shows a substrate processing apparatus 1 that maybe used in embodiments of the invention. The vertical direction in FIG.2 is defined as the z-direction, whereas the horizontal direction shownin FIG. 2 is defined as the y-direction. Additionally, a directionperpendicular to both the y-direction and the z-direction and extendinginto and out of the paper is defined as the x-direction. Furthermore, arotational direction corresponding to rotation about an axis directed inthe x-direction, i.e. x-axis, is defined as the Rx, a rotationaldirection corresponding to rotation about an axis directed in they-direction, i.e. y-axis, is defined as the Ry-direction, and, finally,a rotational direction corresponding to rotation about an axis directedin the z-direction, i.e. z-axis, is defined as the Rz-direction.

In this embodiment, the apparatus 1 comprises a vacuum chamber 50positioned on top of a base plate 52. The apparatus 1 further comprisesa support frame 60 placed within the vacuum chamber 50. The supportframe 60 is preferably made of a material with sufficient stiffness toprovide support without deformation, for example a suitable metal suchas aluminum. Furthermore, in particular in applications using chargedparticle beamlets, the material is non-magnetic.

The radiation projection system 20, which is only partially shown inFIG. 2, takes the form of a column and is placed in a body 62 foraccommodating the column. Body 62 will hereafter be referred to assupport body 62. The radiation projection system 20 is further supportedby and vibrationally decoupled from the support frame 60. In thisembodiment, the support body 62 is connected to the support frame 60 viaan intermediate body 64. The intermediate body 64 may take the form of aplate or a number of plates connected to each other. The intermediatebody 64 may comprise one or more cut-outs and/or may contain portions ofsmaller thickness to reduce weight. The material of the intermediatebody is preferably a non-magnetic material, preferably a non-magneticmetal. The intermediate body 64 enables a decoupling of vibrations inthe z-direction and vibrations in the x, y and Rz-directions.

The support frame 60 is connected to the intermediate body 64 by meansof one or more spring elements 66, such as leaf springs. A leaf springhas well-defined vibrational properties and may comprise at least twosubstantially parallel elongated plates. The thickness and length ofthese plates largely determine the eigenfrequency of the leaf spring.The spring elements 66 may be provided with damping elements to enablevibrational damping, particularly in the z-direction. The springelements 66 are arranged for decreasing the influence of externalvibrations on the position of the support body 62. By suitable selectionof parameters such as shape, size and material of the spring elements66, the incoupling of particular frequency components in externalvibrations may be minimized. In particular, the spring elements 66enable a decoupling of vibrations in the z-direction as well asvibrations in a rotational direction about the x-direction axis and they-direction axis, i.e. Rx and Ry respectively.

The support body 62 is also connected to the intermediate body 64. Theconnection between the body 62 and the body 64 is by means of at leastone rod-like structure, further referred to as pendulum rod 68. The atleast one pendulum rod 68 should be sufficiently strong to carry thesupport body 62, which may have a mass of several hundreds of kilograms,and capable of permitting the support body 62 to swing. The intermediatebody 64 and/or the support body 62 may be provided with damping elementsto dampen vibrations in the horizontal plane and preferably also todampen vibrations in a rotational direction about the z-direction axis,i.e. Rz.

The intermediate body 64 enables a decoupling of vibrations in thez-direction and vibrations in the x, y and Rz-directions. Furthermore,by suitable positioning of the connection positions of the intermediatebody 64 with the spring elements 66, the eigenfrequencies in thez-direction that may couple into the support body 62 may be set.Similarly, by suitable positioning of the one or more connectionpositions of the intermediate body 64 with the one or more pendulum rods68, the eigenfrequencies in Rz-direction that can couple into thesupport body 62 may be set. The eigenfrequencies in the x andy-directions may be set by choosing the length of the one or morependulum rods 68. Consequently, the use of an intermediate body 64provides design freedom regarding the setting of eigenfrequencies of thesystem.

In lithographic application, in particular in case charged particlebeamlets are used for exposing of a substrate to be processed, thevibration isolation requirements are generally more strict for x-, y-and Rz-directions than for z-, Rx- and Ry-directions. Vibrations in thex, y and Rz-direction may have a significant influence on beamletpositioning, which may lead to exposure position errors. On the otherhand, vibrations in the z, Rx and Ry directions have an influence on thebeamlet spot size on the target surface of the substrate to beprocessed. Charged particle beamlets in lithographic systems preferablyhave a relatively large depth of focus. Consequently, a small deviationin a direction away from the focal plane is of less significance for thequality and reliability of the exposed pattern, than the exposureposition errors discussed above.

In lithographic applications, preferably, the eigenfrequencies in thez-direction are chosen to be below 15 Hz, preferably below 5 Hz, whereasthe eigenfrequencies in the x, y and Rz-directions are chosen to bebelow 3 Hz, preferably below 1 Hz. Specific choices of eigenfrequenciesmay depend on the bandwidth of the system responsible for compensatingvibrations, for example control system 40.

The substrate support structure 30, which carries a substrate 70 to beprocessed, is placed on top of a chuck 80. The chuck 80 is provided ontop of a Y-stage 90 for moving the chuck 80 in the y-direction, and anX-stage 92 arranged for movement in the x-direction.

In the shown embodiment, the Y-stage 90 comprises positioners 94 formoving a member 96 in the Y-direction. The positioners 94 typically takethe form of electromotors, preferably linear motors, preferablycomprising Lorentz-type actuators. In a Lorentz-type actuator theapplied force is linearly proportional to the current and the magneticfield. Furthermore, the Y-stage 90 is provided with a gravitycompensation spring 98 for decoupling vibrations in the support frame 60from the substrate support structure 30 and the substrate 70 providedthereon.

FIG. 3 shows a more detailed view of a portion of the substrateprocessing apparatus 1 of FIG. 2. As described above, the column in asubstrate processing apparatus is preferably vibrationally decoupled insuch a way that only very low frequencies can couple into the columnfrom the outside world. In particular in lithographic applications, theradiation generated by a radiation source is modulated before beingprojected in accordance with a predetermined pattern. To supply thepattern, one or more masks may be used. Alternatively, a pattern may becreated by sending control data to deflectors which, in dependence ofthe control signal value that they receive, block a predeterminedportion of radiation or allow that radiation portion to be projected onthe substrate to be processed. Such control data may be sent viaelectric signals, but may also be sent optically, for example viaoptical fibers. Additionally, projecting charged particle beams such aselectron beams requires the application of suitable voltages tocomponents within the column.

Furthermore, the use of a mask and/or deflectors results in a generationof heat caused by the radiation that is blocked within the column. Inview of the ever increasing demand for smaller structures, and theextremely high costs related to occupying space within a semiconductorproduction facility, there is often insufficient space for sufficientpassive cooling. Therefore, in many cases, components within alithographic apparatus are actively cooled, for example by a suitablesupply of cooling fluid.

In FIG. 3, the area within the dashed lines represents a space 100reserved for one or more of electrical wires, optical fibers and coolingconduits for abovementioned purposes. It will be clear that the supplylines should not jeopardize the beneficial design with respect to thevibrational decoupling. In other words, the supply lines should bearranged in such a way that vibrations coupling into the system alsoremain below the desired maximum frequency.

FIG. 4 shows an elevated side view of a support body 62 provided with anarrangement to accommodate electrical wiring 110, optical fibers 120 anda cooling arrangement 130 comprising one or more fluid conduits. Theradiation projection system is not shown to enhance clarity. The wiring110, fibers 120 and cooling arrangement 130 are all provided within thespace denoted by area 100 in FIG. 3.

In the embodiment of FIG. 4 the cooling arrangement 130 comprises aplurality of tubes 131. The tubes 131 are preferably rigid and attachedto the support body 62 to avoid movement of the tubes 131 relative tothe support body 62 due to varying amounts of fluid running throughthem. FIG. 4 merely shows an example of a configuration of tubes 131. Asshown in FIG. 4, the tubes 131 may be grouped together.

The support body 62 is further provided with side walls 135, of whichonly two walls 140 are shown for clarity. The walls 135 may comprise ashielding material, such as a mu metal or the like, for shielding theradiation projection system 20 from external electromagnetic fields.

One or more of the side walls 135 may be provided with one or moreprotrusions 112, 122 arranged to enable draping the electrical wiring110 and the optical fibers 120 respectively in such a way that theelectrical wires 110 and the fibers 120 form a U-shaped bend at a heightlevel below the respective protrusion 112, 122. By hanging the wires 110and/or fibers 120 in such a way, vibrations will not reach the supportbody 62. The U-shaped bend effectively inhibits the vibrations toprogress. Unfortunately, it is impossible to use a similar arrangementto inhibit vibrations to couple into the support body 62 via ordinarycooling tubes.

FIG. 5 schematically shows a fluid transfer system 150 according to anembodiment of the invention. The fluid transfer system 150 is arrangedfor providing fluid to and removing fluid from the cooling arrangementof the radiation projection system 20. The fluid transfer system 150comprises at least one tube 140 fixed at two points 151, 152 within thesubstrate processing apparatus 10. The points 151, 152 may be referredto as anchor points or fixed points 151, 152. The portion of the fluidtransfer system 150 that is arranged for transferring fluid between thefixed points 151, 152 may be referred to as the flexible portion of thefluid transfer system 150.

In the fluid transfer system 150 depicted in FIG. 5 the system comprisesa plurality of tubes 140 for providing fluid to the cooling arrangement,and another plurality of tubes 140 for removing fluid from the coolingarrangement. As will be explained with reference to FIG. 6, the tubes140 for providing fluid and the tubes 140 for removing fluid may bespecifically arranged to avoid heat transfer between the tubes 140.Alternatively, the fluid transfer system 150 may comprise only one tube140, or merely one tube 140 for providing fluid to the coolingarrangement and merely one tube 140 for removing fluid from the coolingarrangement. In fact, any number of tubes 140 may be possible.

The first anchor point 151 is preferably connected to the support frame60 whereas the second anchor point 152 is preferably connected to theradiation projection system 20 which comprises the cooling arrangement.The main portions of the tubes 140 are arranged in curved fashion in aplane, preferably the xy-plane. The radius of curvature preferablycoincides with the natural curvature tubes obtain while they are beingmanufactured. End portions of the tubes 140 have an orientationsubstantially perpendicular to the plane. In FIGS. 5 and 6, the tube endportions facing upwards are arranged for connection with the supportframe 60, whereas the tube end portions facing downwards are arrangedfor connection with the cooling arrangement of the radiation projectionsystem 20.

Because the tubes 140 do not form a straight connection between theanchor points 151, 152, but instead form a curved connection, in FIG. 5in the form of a loop, vibrations are attenuated over a longer distance,which allows for more efficient vibration decoupling. The orientation ofthe tubes 140 in a curved fashion in a single plane allows for vibrationattenuation in that plane. For example, in case the plane correspondswith the xy-plane, as preferably the case if the substrate processingapparatus corresponds to the apparatus depicted in FIG. 2, the curvedtubing arrangement allows for attenuation of the vibrations in thex-direction, the y-direction, and the rotational direction substantiallyperpendicular to the xy-plane, i.e. the Rz-direction.

Preferably, the tubes 140 are supported by one or more suspensionholders 160 along their trajectory between the anchor points 151, 152.The use of one or more suspension holders 160 reduces tube bending underthe influence of gravity. As a result of such bending, one or more tubesmay contact the support frame 60 or a structure connected thereto, whichwould eliminate the vibration decoupling. An embodiment of a suspensionholder 160 is schematically depicted in FIG. 7.

By suitable selection of the type and number of tubes as well as thenumber of suspension holders, if any, the stiffness of the fluidtransfer system may be defined such that vibrations above apredetermined maximum frequency as suppressed. In particular, in theembodiment depicted in FIG. 5, attenuation of vibrations in the x, y andRz direction is progressively established over the entire length betweenanchor points 151 and 152. On the other hand, attenuation of vibrationsin the Rx, Ry and z-directions effectively take place between the anchorpoint 152 and the suspension holder 160 closest to the anchor point 152.As a result, the predetermined maximum frequency that is allowed toadvance to the radiation projection system may differ per vibrationdirection. In particular, in the embodiment depicted in FIG. 5 thepredetermined maximum frequency in the x, y and Rz-directions istypically lower than the predetermined maximum frequency in the Rx, Ryand z-directions.

Suitable materials for the one or more tubes 140 would beperfluoroalkoxy (PFA) and polytetrafluoroethylene (PTFE), the latterbeing known under the trade name Teflon®. In this embodiment, PFA ispreferred because it is melt-processable using conventional processingtechniques including but not limited to injection molding and screwextrusion.

The use of curved tubes, preferably with a curvature that substantiallycorresponds to the curvature that is naturally provided to the tubesduring manufacturing or fabrication, i.e. their “natural curvature”,allows for attenuation of vibrations along a relatively long trajectory.In particular, the tubes may be oriented and placed in such a way thatthe fluid transfer system has a predetermined maximum stiffness.Preferably, the predetermined maximum stiffness is lower than 500 N/m,more preferably lower than 400 N/m. A low stiffness results in a reducedincoupling of vibrations. In particular, the cut-off frequency ofvibrations that are coupled into the cooling arrangement is lower incase the maximum stiffness of the fluid transfer system is reduced.

Providing a predetermined stiffness for the flexible portion of thefluid transfer system may include different selections of suitableparameters and conditions. For example, the length, diameter and wallthickness of the one or more tubes 140 may be suitably selected.Alternatively, or additionally, the curvature of the one or more tubes140 may be suitably selected. Furthermore, as the stiffness of theflexible portion may depend on the fluid that is transferred through thefluid transfer system during operational use, the fluid transfer systemmay comprise a fluid supply system for regulating parameters of thefluid flow in the fluid transfer system. Exemplary parameters include,but are not limited to fluid type, fluid volume and fluid pressure.

The fluid being transferred via the fluid transfer system towards andfrom the cooling arrangement may be liquid, a gas or a combination ofthe two. In many applications, water is a suitable cooling fluid.

FIG. 6 schematically shows the fluid transfer system 150 of FIG. 5connected to an additional support frame 170. The additional supportframe 170 is connected to the support frame 60 by via couplingstructures 171. Furthermore, the additional support frame 170 isarranged to support the suspension holders 160 used to support theweight of the tubes 140. Furthermore, the additional support frame 170may be used to outline the position of the fluid transfer system 150within the substrate processing apparatus. The additional support frame170 may be manufactured by cutting and bending plate material, forexample aluminum, optionally in combination with welding techniques.

FIG. 6 further shows that the end portions of the tubes 140 facingupwards are connected with the support frame 60 via flanges 180 and 181,each flange preferably 180, 181 being arranged to accommodate solelytubes that transfer fluid towards or away from the radiation projectionsystem 20 respectively. Similarly, the end portions of the tubes 140facing downwards are connected to the radiation projection system 20,preferably to the cooling arrangement provided therein, via flanges 190and 191. Again, each flange 190, 191 is preferably arranged toaccommodate solely tubes that transfer fluid towards or away from theradiation projection system 20 respectively.

FIG. 7 schematically shows a suspension holder 160 that may be used inthe fluid transfer system of FIG. 5. The suspension holder 160comprising a frame 200 in which one or more support elements 210 areprovided for supporting the one or more tubes 140. Preferably, multiplesupport elements 210 are used that can be connected in such a way thatthe support elements form a support structure provided with a pluralityof holes for accommodating the tubes 140. The support structure isvibrationally decoupled in x, y and Rz-directions from the frame 200 bymeans of supporting poles 220 and spring elements 230. The supportingpoles 220 have rounded ends 221 that allow for movement in the x, y andRz-directions. The spring elements 230 may take the form of springs.

Preferably, the support elements 210 have dimensions that allow thecreation of the support structure in a modular fashion. In suchembodiment, first, the lowest support element 210 is provided on top ofwhich one or more tubes are placed. Subsequently, a second supportelement 210 is placed on top of the lowest support element 210, therebyenclosing the tubes 140 already resting on the lowest support element210. The second support element 210, in its turn, may be provided withrecessions that allow placement of further tubes 140. Then a thirdsupport element 210 may be placed on top of the second support element210 to enclose the tubes 140 that are placed in the recessions of thesecond support element 210. This stacking of support elements 210continues until all tubes are suitably enclosed as depicted in FIG. 7.

Preferably, in case tubes 140 of different diameter are used, the tubeswith largest diameter are supported at a relatively centered position,whereas tubes 140 with a smaller diameter may be located near the edgeof the support structure. Such allocation of tubes results in a morestable structure.

Preferably, the holes in the support structure for allowing the tubes topass therethrough are of such dimensions that the tubes may movesomewhat in a transverse direction within the holes. In other words, insome embodiments, the tubes do not fit tightly in the holes, but ratherfit loosely. In particular if the curvature of a tube differs from itsnatural curvature, resilient forces may occur which may move the tubeslight inwards or outwards. If the tubes would fit tightly, suchsideways transfer could result in a similar movement of the supportstructure of the suspension holder 160, which, in its turn, may resultin contact between the suspension holder 160 and the support frame 60 ora structure connected thereto, for example additional support frame 170.Consequently, the vibrational decoupling of the support structure wouldbe eliminated.

FIG. 8 schematically shows a fluid transfer system 250 according toanother embodiment of the invention. The fluid transfer system 250 isarranged for providing fluid to and removing fluid from the coolingarrangement of the radiation projection system 20 and comprises at leastone tube 240 fixed at two points within the substrate processingapparatus 10. The tube 240 comprises at least two straight portions 252and at least one corner portion 254 between the two points. The straightportions 252 are flexible compared to the one or more corner portions254. In other words, the one or more corner portions 254 have a higherstiffness than the straight portions 252.

The straight portions 252 make up the largest part of the tube 240, i.e.sum of the lengths of the straight portions 252 exceeds 50% of thelength of the tube 240. Preferably the sum of the lengths of thestraight portions 252 makes up at least 70% of the length of the tube240. Consequently, the tube 240 is mostly flexible, but stiff in thecorners. The flexible straight portions 252 within the fluid transfersystem 250 enable attenuation of vibrations progressing towards thesupport body 62 above a predetermined maximum frequency. The one or morestiff corner portions 254 are capable of sustaining pressure increases,which for example may avoid straightening of the tube 240 due to fluidrunning through the tube. Suitable materials for the one or more tubes140 would again be perfluoroalkoxy (PFA) and polytetrafluoroethylene(PTFE), the latter being known under the trade name Teflon®.

The use of one or more tubes having straight portions 252 and one ormore corner portions 254 provides design freedom with respect to thestiffness of the fluid transfer system. In particular, the fluidtransfer system may be designed to have a predetermined maximumstiffness. Preferably, the predetermined maximum stiffness is smallerthan 500 N/m. Providing a predetermined maximum stiffness may involvesimilar selections and considerations discussed with reference to theembodiment shown in FIG. 5.

The fluid being transferred via the fluid transfer system towards andfrom the cooling arrangement may be liquid, a gas or a combination ofthe two. In many applications, water is a suitable cooling fluid.

FIG. 9 schematically shows a cross-sectional view of an embodiment of acorner portion 254 for use in the fluid transfer system of FIG. 8. Thecorner portion 254 comprises a stiffening member 260. The stiffeningmember 260 is a structure provided with a hollow opening 262 in theshape of a bended tube. Preferably, the hollow opening 262 accommodatesthe tube 240 and guides the tube around a corner. Alternatively, thehollow opening 262 can be used as a conduit to which straight portions252 of the tube are attached. The stiffening member 260 prevents thetube from straightening due to fluid running through the tube. Thestiffening member 260 is preferably made of a non-magnetic material.Furthermore, the material preferably enables easy manufacturing and is amaterial of limited weight. A suitable material for the stiffeningmember 260 is aluminum.

The stiffening member 260 may be connected to the support frame 60 bymeans of a spring element 270. Such connection provides structuralintegrity to the cooling transfer system 250 within the substrateprocessing apparatus, while limiting the influence of externalvibrations. The size and shape of the spring element 270 depends on thedesired structural integrity and the requirements regarding the(frequencies of the) vibrations that are to be attenuated.

FIGS. 8 and 9 show a fluid transfer system 250 with a single tube 240.However, in some embodiments, the fluid transfer system 250 comprises aplurality of tubes. In such system 250, each tube may be arranged asshown in FIGS. 8 and 9, i.e. fixed at two points and comprising at leasttwo relatively flexible straight portions and at least one relativelystiff corner portion between the two points.

FIG. 10 schematically shows a cross-sectional view of an embodiment of astiffening member 260 that may be used in embodiments of the inventionin which the fluid transfer system 250 comprises a plurality of tubes,such as the fluid transfer system of FIG. 8. The stiffening member 260is provided with a plurality of openings 262 for guiding fluid in adesired direction. Similar to the embodiment shown in FIG. 9, theopenings 262 may either be used as conduits for guiding the fluid, orthey may accommodate a portion of the tubes 240.

The fluid transfer system 250 may be surrounded by a tubular housing280. The tubular housing 280 may be used to protect the fluid transfersystem 250. Furthermore, in case the fluid transfer system 250 isprovided in a vacuum environment, for example in a vacuum chamber 50 asshown in FIG. 2, the tubular housing 280 may be arranged for blockingparticles emitted from the tubes 240 from entering into the vacuum.Preferably, the tubes 240 do not directly contact the housing 280. Thestiffening members 260 are connected to the housing 280, preferably viaone or more spring elements 290 to ensure vibrational decoupling fromthe environment. The tubular housing 280 is preferably relatively stiff,and is preferably rigidly connected to the support frame 60 via aconnection 272 to provide sufficient structural integrity to the tubularhousing 280.

Alternatively, the tubular housing 280 may be connected to the supportframe 60 via one or more spring elements, such as spring elements 270.In such case, the stiffness of the spring elements 270 and 290 is to beproperly tuned to achieve an effective vibrational decoupling of thestiffening member 260 from the support frame 60.

FIG. 11 shows an elevated side view of a fluid transfer system 250within a tubular housing 280. The system 250 comprises a plurality oftubes 240. The straight portions 252 of each tube are free of contactingstraight portions of other tubes 240. As a result, vibrations withinneighboring tubes 240 have a negligible effect on the vibrationattenuation performance of a tube 240. In addition to stiffening members260 in corner portions 254 of the tubes 240, the fluid transfer system250 comprises a further stiffening member 265 at an end of the tubes.The further stiffening member 265 fixates the connection positions ofthe fluid transfer system 250 at its end points. For example, thefurther stiffening member 265 may be used to fixate the end points ofthe tubes 240 of the fluid transfer system for connection tocorresponding conduits within the cooling arrangement 230 of theradiation projection system 20. The further stiffening member 265 may besimilar to stiffening member 260. However, the one or more openings 262do not necessarily have a curved portion for guiding fluid around acorner.

FIG. 12 schematically shows a cross-sectional view of a connection of afluid transfer system 250 with a cooling arrangement 230 according to anembodiment of the invention. In the embodiment depicted in FIG. 12, thefluid transfer system 250 comprises a plurality of tubes 240 surroundedby a housing 280. The housing 280 is preferably shaped in a waysubstantially corresponding to the shape formed by the plurality oftubes 240. In the shown embodiment, the housing thus takes the faun of atubular housing 280.

The cooling arrangement 230 comprises a corresponding plurality of tubes231. The way in which the tube ends of the cooling arrangement and thetube ends of the fluid transfer system 250 are connected to each otheris not explicitly shown. However, it will be understood that this may bedone in a way generally known in the art. The tubular housing 280 isprovided with a membrane 300. The membrane 300 is arranged forseparating a space within the tubular housing 280 from externalinfluences, in particular from a vacuum environment. The membrane 300 isprovided with one or more openings through which the one or more tubesof the fluid transfer system 250 protrude.

In case the cooling arrangement 230 is subjected to a vacuumenvironment, particles created within the tubular housing 280, forexample due to outgassing, may leak towards the vacuum environment viathe membrane openings. To reduce such leakage, the tubular housing 280is preferably provided with an outlet 310 that may be connected to apump, preferably a vacuum pump. Alternatively, or additionally, leakageis reduced by providing flexible portions 305 to positions in closeproximity of or at the edges of the membrane openings. The flexibleportions 305 extend from the membrane 300 onto the tubes forming a weakseal. The flexible portions 305 reduce the size of the openings, and maytherefore further reduce leakage of particles from the internal space ofthe housing 280 towards the vacuum environment. Furthermore, since theportions 305 form a weak seal, the advancement of any undesiredvibrations via the housing 280 and the membrane 300 towards theradiation projection system is avoided.

The invention has been described by reference to certain embodimentsdiscussed above. It will be recognized that these embodiments aresusceptible to various modifications and alternative forms well known tothose of skill in the art without departing from the spirit and scope ofthe invention. Accordingly, although specific embodiments have beendescribed, these are examples only and are not limiting upon the scopeof the invention, which is defined in the accompanying claims.

Clauses

C1. Substrate processing apparatus (10), such as a lithographicapparatus or an inspection apparatus, comprising:

-   -   a support frame (60);    -   a radiation projection system (20) for projecting radiation onto        a substrate (70) to be processed, the radiation projection        system comprising a cooling arrangement (130) and being        supported by and vibrationally decoupled from the support frame        such that vibrations of the support frame above a predetermined        maximum frequency are substantially decoupled from the radiation        projection system; and    -   a substrate support structure (60) provided with a surface for        supporting the substrate to be processed;        the substrate processing apparatus further comprising a fluid        transfer system (150;250) for providing fluid to and removing        fluid from the cooling arrangement of the radiation projection        system, wherein the fluid transfer system comprises at least one        tube (140;240) fixed at at least two points within the        apparatus, the fluid transfer system comprising a flexible        portion (140;252) extending between the two fixed points and        including the at least one tube, a first one of the fixed points        being fixed relative to the radiation projection system and a        second one of the fixed points being moveable relative to the        radiation projection system,

wherein at least a substantial part of the flexible portion extends intwo dimensions over a plane substantially parallel to the surface of thesubstrate support structure for supporting the substrate to beprocessed, and

wherein the stiffness of the flexible portion between the two points isadapted to substantially decouple vibrations at the second fixed pointwhich are above the predetermined maximum frequency from the first fixedpoint.

C2. Apparatus according to clause 1, wherein the second one of the fixedpoints is fixed relative to the support frame.

C3. Apparatus according to clause 1 or 2, wherein the fluid transfersystem has a predetermined maximum stiffness.

C4. Apparatus according to clause 3, wherein the predetermined maximumstiffness is lower than 500 N/m, preferably lower than 400 N/m.

C5. Apparatus according to any one of the preceding clauses, wherein thelength, diameter, and wall thickness of the at least one tube isselected to provide a predetermined stiffness of the flexible portion ofthe fluid transfer system.

C6. Apparatus according to any one of the preceding clauses, wherein thecurvature of the at least one tube is selected to provide apredetermined stiffness of the flexible portion of the fluid transfersystem.

C7. Apparatus according to any one of the preceding clauses, wherein thefluid transfer system further comprises a fluid supply system forregulating the volume and pressure of fluid in the fluid transfer systemto provide a predetermined stiffness of the flexible portion of thefluid transfer system.C8. Apparatus according to any one of the preceding clauses, wherein oneor more tubes of the fluid transfer system are made of a materialcomprising at least one of perfluoroalkoxy and polytetrafluoroethylene.C9. Apparatus according to any one of the preceding clauses, wherein thecooling arrangement comprises one or more conduits, and wherein one ormore tubes of the fluid transfer system are connected to a correspondingconduit.C10. Apparatus according to any one of the preceding clauses, whereinthe support frame, the radiation projection system, the substratesupport structure, and the fluid transfer system are placed in a vacuumchamber (50).C11. Apparatus according to any one of the preceding clauses, whereinthe at least one tube (140) is oriented in a curved fashion in a planesubstantially parallel to the surface of the substrate support structurefor supporting the substrate to be processed.C12. Apparatus according to clause 11, wherein the curvature of the atleast one tube corresponds with the natural curvature of the at leastone tube obtained during fabrication thereof.C13. Apparatus according to clause 11 or 12, further comprising at leastone suspension holder (160) comprising a support structure for holdingthe at least one tube at a location along its length, the supportstructure being vibrationally decoupled from the support frame forvibrations in a direction within a plane substantially parallel to thesurface of the substrate support structure for supporting the substrateto be processed, as well as in a direction about an axis substantiallyperpendicular to said plane.C14. Apparatus according to clause 13, wherein the suspension holdercomprises a frame (200) connected to the support structure by means ofat least two supporting poles (220) and one or more spring elements(230).C15. Apparatus according to clause 13 or 14, wherein the fluid transfersystem comprises a plurality of tubes (140), each tube being fixed attwo points and each tube being oriented in a curved fashion in a planesubstantially parallel to the surface of the substrate support structurefor supporting the substrate to be processed, and wherein the supportstructure of the at least one suspension holder is arranged for holdingthe plurality of tubes at a location along their length such that thetubes do not contact each other.C16. Apparatus according to clause 15, wherein the tubes have differentdiameters, and wherein the tubes of larger diameter are more centrallysupported by the support structure of the at least one suspensionholder.C17. Apparatus according to clause 15 or 16, further comprising anadditional support frame (170) connected to the support frame forsupporting the at least one suspension holder.C18. Apparatus according to any one of clauses 11-17, wherein endportions of the at least one tube are oriented in a directionsubstantially perpendicular to the plane of the surface of the substratesupport structure for supporting the substrate to be processed.C19. Apparatus according to any one of clauses 1-10, wherein the atleast one tube of the fluid transfer system comprises at least twostraight portions (252) and at least one corner portion (254) betweenthe two points, wherein the at least two straight portions are flexiblecompared to the at least one corner portion, and wherein the lengths ofthe straight portions make up a largest part of the length of the atleast one tube.C20. Apparatus according to clause 19, wherein the sum of the lengths ofthe straight portions makes up at least 70% of the length of the atleast one tube.C21. Apparatus according to clause 19 or 20, wherein the fluid transfersystem comprises a plurality of tubes, each tube being fixed at twopoints and comprising at least two straight portions and at least onecorner portion between the two points, wherein the at least two straightportions are flexible compared to the at least one corner portion.C22. Apparatus according to clause 21, wherein the lengths of thestraight portions make up a largest part of the tube lengths.C23. Apparatus according to clause 22, wherein the sum of the lengths ofthe straight portions make up at least 70% of the tube lengths.C24. Apparatus according to any one of clauses 21-23, wherein thestraight portions of each tube are free of contacting straight portionsof other tubes.C25. Apparatus according to any one of the clauses 19-24, wherein the atleast one corner portion comprises a stiffening member (260) providedwith an opening (262) for transferring fluid around a corner.C26. Apparatus according to clause 25, wherein the stiffening member isconnected to the support frame by means of a spring element (270).C27. Apparatus according to any one of clauses 19-26, wherein thesupport frame, the radiation projection system, the substrate supportstructure, and the fluid transfer system are placed in a vacuum chamber(50), and wherein the fluid transfer system is surrounded by a housing(180), preferably a tubular housing.C28. Apparatus according to clause 27, wherein the housing, at an end atwhich the one or more tubes (240) are attached to the coolingarrangement, is provided with a membrane (300) for separating a spacewithin the housing from external influences, the membrane being providedwith one or more openings through which the one or more tubes protrude.C29. Apparatus according to clause 28, wherein the membrane is providedwith flexible portions (305) in areas within the openings, wherein theflexible portions extend from the membrane onto the tubes.C30. Apparatus according to clause 28 or 29, wherein the housing isprovided with an outlet (310) connectible to a pump.C31. Apparatus according to any one of the preceding clauses, furthercomprising:

-   -   a support body (62) for accommodating the radiation projection        system; and    -   an intermediate body (64) connected to the support frame by        means of at least one spring element (66);        wherein the support body is connected to the intermediate body        by means of at least one pendulum rod (68).        C32. Apparatus according to clause 31, wherein the at least one        spring element is a leaf spring.        C33. Apparatus according to clause 31 or 32, wherein the support        body is provided with side walls (135) surrounding the radiation        projection system, the side walls comprising a shielding        material for shielding the radiation projection system from        external electromagnetic fields.        C34. Apparatus according to any one of the preceding clauses,        wherein the radiation projection system is a multi-beamlet        charged particle lithographic apparatus.        C35. Apparatus according to clause 34, wherein the multi-beamlet        charged particle lithographic apparatus comprises:    -   a beam generator (21) for generating a plurality of charged        particle beamlets;    -   a beamlet blanker array (22) for patterning the plurality of        beamlets in accordance with a pattern; and    -   a projection system (23) for projecting the patterned beamlets        onto a target surface of a substrate provided on the target        support structure.        C36. Substrate processing apparatus (10), such as a lithographic        apparatus or an inspection apparatus, comprising:    -   a support frame (60);    -   a radiation projection system (20) for projecting radiation onto        a substrate (70) to be processed, being supported by and        vibrationally decoupled from the support frame such that        vibrations of the support frame above a predetermined maximum        frequency are substantially decoupled from the radiation        projection system;    -   a fluid transfer system (150;250) for transferring fluid to and        removing fluid from the radiation projection system; and    -   a substrate support structure (60) provided with a surface for        supporting the substrate to be processed;        wherein the fluid transfer system comprises one or more tubes        for transferring fluid, wherein a portion of the one or more        tubes extends in a two dimensions over a plane substantially        parallel to the surface of the substrate support structure for        supporting the substrate to be processed.        C37. Apparatus according to clause 36, wherein the portion of        the one or more tubes extends over the plane in the form of a        loop.        C38. Apparatus according to clause 37, further comprising at        least one suspension holder for holding the portion of the one        or more tubes extending in two dimensions.        C39. Apparatus according to clause 38, further comprising an        additional support frame (170) connected to the support frame        for supporting the at least one suspension holder.        C40. Apparatus according to any one of clauses 35-39, wherein        the radiation projection system comprises a cooling arrangement        (130), and wherein the fluid transfer system is adapted for        transferring cooling fluid to and removing cooling fluid from        the cooling arrangement.

The invention claimed is:
 1. A beam exposure apparatus, comprising: asupport frame; a beam projection system for projecting beams onto atarget, the beam projection system comprising a cooling arrangement andbeing supported by the support frame; a fluid transfer system forproviding fluid to and removing fluid from the cooling arrangement ofthe beam projection system, wherein the fluid transfer system comprisesa plurality of tubes, a first fixation element and a second fixationelement, wherein the plurality of tubes are fixed at least by the firstand second fixation elements at a first fixed point and a second fixedpoint within the apparatus; and a support structure for holding theplurality of tubes together at a location along their length between thefirst fixed point and the second fixed point such that the plurality ofthe tubes do not contact each other, wherein the plurality of tubes ofthe fluid transfer system comprise a flexible portion extending betweenthe first and second fixed points, the first fixed point being fixedrelative to the support frame, and the second fixed point being fixedrelative to the beam projection system and to the cooling arrangement,and wherein the first and second fixed points and at least a substantialpart of the flexible portion are arranged in a plane, so that theflexible portion extends substantially along a curve in the plane. 2.The apparatus according to claim 1, wherein the plurality of tubesinclude a length, diameter, and wall thickness that are selected toprovide a predetermined stiffness of the flexible portion of the fluidtransfer system.
 3. The apparatus according to claim 1, wherein thefluid transfer system further comprises a fluid supply system forregulating the volume and pressure of fluid in the fluid transfer systemto provide a predetermined stiffness of the flexible portion of thefluid transfer system.
 4. The apparatus according to claim 1, whereinthe plurality of tubes are oriented in a curved fashion in the plane inthe form of a loop.
 5. The apparatus according to claim 1, furthercomprising a target support structure provided with a surface forsupporting the target, wherein each tube is-oriented in a curved fashionin a plane substantially parallel to the surface of the target supportstructure.
 6. The apparatus according to claim 4, wherein end portionsof the plurality of tubes are oriented in a direction substantiallyperpendicular to the plane.
 7. The apparatus according to claim 1,wherein the plurality of tubes of the fluid transfer system comprise atleast two straight portions and at least one corner portion between thetwo points, wherein the at least two straight portions are flexiblecompared to the at least one corner portion, and wherein the lengths ofthe straight portions make up a largest part of the length of theplurality of tubes.
 8. The apparatus according to claim 1, wherein theplurality of tubes of the fluid transfer system comprise a first endportion and a second end portion, the first and second end portionsbeing oriented in a direction with an angle with respect to the plane,and wherein the first end portion is connected to the support frame andthe second end portion is connected to the beam projection system. 9.The apparatus according to claim 1, wherein the plurality of tubescomprise an end portion extending substantially along a center line ofthe beam projection system.
 10. The apparatus according to claim 1,wherein the flexible portion extends substantially along the curve inthe plane substantially parallel to a beam incident surface of thetarget.
 11. A fluid transfer system for providing fluid to and removingfluid from a cooling arrangement, the fluid transfer system comprising:a plurality of tubes; a first fixation element for fixing the pluralityof tubes to a support frame; a second fixation element for fixing theplurality of tubes to the cooling arrangement, the support framearranged to support the cooling arrangement, wherein the plurality oftubes are fixed by the first and second fixation elements at a firstfixed point and a second fixed point, the plurality of tubes having aflexible portion extending between the first and second fixed points;and a support structure for holding the plurality of tubes together at alocation along their length between the first fixed point and the secondfixed point such that the plurality of the tubes do not contact eachother, wherein the first and second fixation elements are moveable withrespect to each other, and wherein the first and second fixed points andat least a substantial part of the flexible portion are arranged in asame plane, so that the flexible portion extends substantially along acurve in the same plane.
 12. The fluid transfer system according toclaim 11, wherein the flexible portion extends in a curved fashion inthe form of a loop in the plane.
 13. The fluid transfer system accordingto claim 11, wherein the support structure comprises one or moresuspension holders arranged along the portion of the plurality of tubesextending between the first and second points, each suspension holderbeing arranged to reduce bending under the influence of gravity.
 14. Thefluid transfer system according to claim 11, further comprising a firstend portion and a second end portion, the first and second end portionsbeing oriented in a direction with an angle with respect to the plane.15. A support arrangement for supporting a beam projection system in abeam exposure apparatus, the support arrangement comprising: a supportbody for supporting the beam projection system configured to projectbeams onto a target; electrical wiring for supplying voltages tocomponents within the beam projection system and/or for supplyingcontrol data for modulation of beams to be projected onto a surface ofthe target by the beam projection system; and a cooling arrangementcomprising one or more fluid conduits for cooling the beam projectionsystem, wherein the electrical wiring and the cooling arrangement beingat least partly accommodated in and/or supported by the support body,and wherein the support arrangement comprises a space that is reservedfor the electrical wiring and the fluid conduits.
 16. The supportarrangement according to claim 15, wherein the cooling arrangementcomprises a plurality of tubes, the tubes being rigid and attached tothe support body.
 17. The support arrangement according to claim 16,wherein the tubes are rigidly attached to the support body.
 18. Thesupport arrangement according to claim 15, wherein the support bodyfurther comprises side walls for at least partly surrounding the beamprojection system.
 19. The support arrangement according to claim 18,wherein the side walls are connected to a base of the support body andextend in a direction substantially perpendicular to the base.
 20. Thesupport arrangement according to claim 18, wherein one or more of theside walls are provided with one or more protrusions enabling drapingthe electrical wiring in such a way that the electrical wires form aU-shaped bend at a height level below the respective protrusion.